LAP2alpha maintains a mobile and low assembly state of A-type lamins in the nuclear interior

Lamins form stable filaments at the nuclear periphery in metazoans. Unlike B-type lamins, lamins A and C localize also in the nuclear interior, where they interact with lamin-associated polypeptide 2 alpha (LAP2α). Using antibody labeling, we previously observed a depletion of nucleoplasmic A-type lamins in mouse cells lacking LAP2α. Here, we show that loss of LAP2α actually causes formation of larger, biochemically stable lamin A/C structures in the nuclear interior that are inaccessible to lamin A/C antibodies. While nucleoplasmic lamin A forms from newly expressed pre-lamin A during processing and from soluble mitotic lamins in a LAP2α-independent manner, binding of LAP2α to lamin A/C during interphase inhibits formation of higher order structures, keeping nucleoplasmic lamin A/C in a mobile state independent of lamin A/C S22 phosphorylation. We propose that LAP2α is essential to maintain a mobile lamin A/C pool in the nuclear interior, which is required for proper nuclear functions.

Budaya Visual pada Website Fakultas Seni Rupa dan Desain Universitas Trisakti

Abstrak Keberadaan website Fakultas Seni Rupa dan Desain, Universitas Trisakti, penting untuk diteliti karena merupakan cermin dari budaya visual institusi yang menampilkannya. Website dapat diakses dengan berbagai perangkat pendukung seperti komputer, laptop, tablet, dan smartphone, baik kondisi pengguna (users) dalam kondisi statik maupun bergerak, serta dalam waktu yang tidak terbatas jam kerja. Metode penelitian tulisan ini adalah deskriptif-kualitatif dengan menggunakan kajian budaya. Kajian budaya dalam tulisan ini mengkaji situs website di institusi Fakutas Seni Rupa dan Desain, Universitas Trisakti dan memberikan gambaran bentuk-bentuk pengetahuan dan perilaku yang diasosiasikan dengan aktifitas sosial atau situs sosial di institusi tersebut. Hasil dari penelitian ini adalah gambaran ide, visi misi, perilaku, serta cita-cita yang hendak dibangun oleh website Fakultas Seni Rupa dan Desain, Universitas Trisakti, yang dapat membangun citra positif bagi masyarakat luas. Kata Kunci: budaya visual, desain, identitas, website AbstractThe existence of the Faculty of Art and Design, Trisakti University, website essential to research because it is a reflection of the institution's visual culture that features it. The website accessible through various devices, such as a computer, a laptop, tablet, smartphone when users at static or mobile state, and within unlimited working hours. This research using descriptive - qualitative with the cultural study approach. The cultural study on this research analyzes the Faculty of Art and Design, Trisakti University, website and providing the picture of knowledge forms and attitudes which associate with social activity and social site in the institution. The result of this research is idea picture, vision, mission, attitude, and the goal that wishes to build by the Faculty of Art and Design, Trisakti University website that can develop a positive image to the larger society. Keywords: design, identity, culture, visual, website

On the hydrodynamics of crystal clustering

The formation of crystal clusters may influence the mechanical behaviour of magmas. However, whether clusters form largely from physical contact in a mobile state during sedimentation and stirring, or require residence in a crystal mush, is not well understood. In this paper, we use discrete-element fluid dynamics numerical experiments to illuminate the potential for clustering from both sedimentation and open-system mixing in a model olivine basalt reservoir for three different initial solid volume per cents. Crystal clustering is quantified using both bulk measures of clustering such as the R index and Ripley's L(r) and g(r) functions and with a variable scale technique called Voronoi tessellations, which also provide orientation data. Probability density functions for the likelihood of crystal clustering under freely circulating conditions indicate that there is nearly an equal likelihood for clustering and non-clustered textures in natural examples. A crystal cargo in igneous rock suites exhibiting a dominance of crystal clusters may be largely sampling magmatic materials formed in a crystal mush. This article is part of the Theo Murphy meeting issue ‘Magma reservoir architecture and dynamics’.

Altering a Fixed Identity: Thinking through Improvisation

"Replacing artist with player as if adopting an alias is a way of altering a fixed identity. And a changed identity is a principle of mobility, of going from one place to another…" (Kaprow, Essays on the Blurring of Art and Life 125-6) This paper explores an experiment in improvisation in which the practices of music, the visual arts, philosophy, and anthropology come together. Calendar Variations (2010-11) draws different kinds of artists into creative experiences through the use of verbal scores. The score invites participation in a process in which the outcome is indeterminate. The experiment raises a question within the group of artists and participants about the nature of artistic practice itself and whether any single aesthetic approach is more appropriate than another. The experiment frames the following questions: Why do we have/institute improvisation in life? Can art particularly inform those situations in life in which the unscripted and contingent challenge us to rethink in situations in which we may be encountering failure either in what is around us or failure in ourselves to cope? Drawing in particular on Allan Kaprow’s articulation of Experimental Art (Essays), informed by Ingold and Hallam’s construct of improvisation as a metaphor for existence (Creativity and Cultural Improvisation), I propose that the radical questioning of certainty in experimental art practices offers a different insight into improvisation, one that deals with experiences of failure. The paper concludes that sustaining uncertainty about what the arts might be has given rise to two possible understandings of visual art, one based on contemplation, and the other on time and duration. Our creative imagination is challenged by the collisions and complementarities of these different understandings to sustain a perpetually mobile state of creativity, akin to "adopting an alias as a way of altering a fixed identity" (Kaprow, Essays).

Rao-Blackwellized Particle Filtering for Mobility Positioning in Mixed Sight Conditions

Mixed sigh conditions include line-of-sight/non-line-of-sight (LOS/ NLOS) conditions, which have adverse impact on the precision for mobility positioning. A first-order Markov model is employed to describe the dynamic transition of sight conditions, which is hidden in measured data. A Rao-Blackwellized Particle filter (RBPF) is proposed to jointly estimate mobile state and the hidden sight state based on the measurement. Simulation results show the effectiveness of the method.

Biomimetic, amorphous granules of polyhydroxyalkanoates: composition, mobility, and stabilization in vitro by proteins

It is a remarkable feature of poly(3-hydroxybutyrate) (PHB) that although the isolated polymer is highly crystalline, native PHB storage granules in cells are only found in an amorphous, mobile state. It has recently been proposed that the failure of PHB granules to crystallize is simply the result of slow nucleation kinetics that are operative for small, isolated particles. In support of this new model, we present here a straightforward procedure by which pure crystalline PHB can be reconstituted into submicron-size, detergent-coated artificial granules. The artificial granules are amorphous and stable in suspension, and they are essentially indistinguishable from their native counterparts in terms of size, morphology, molecular mobility, and density. Furthermore, when the surfactant coating is removed from the artificial granules by dialysis, the granules crystallize, verifying the nucleation hypothesis. In vivo, the PHB granule surface is likely to consist of both polypeptide and lipid; in vitro it is possible to prepare amorphous PHB granules that are stabilized solely by phospholipids or by any of several common proteins (serum albumin, casein, or ovalbumin). Artificial amorphous granules may be prepared from a variety of different bacterial PHAs and from blends of incompatible polyesters.Key words: polyhydroxyalkanoate, poly(3-hydroxybutyrate), granules, nucleation, latex.

Chloride ion substitution in alkali bromide surfaces: cooperative interactions, including a surface transition

Thermodynamic information on surfaces of vacuum -sublimed NaBr and KBr has been obtained by stud y in g equilibrium in: ( a ) halogen exchange between HCl(g) and the surfaces; ( b ) adsorption of HCl an d HBr. Both types of study disclose a transition in the pure KBr surface at 293 K, induced by HCl adsorption. From exchange results, Δ H t = + 18.4 kJ mol -1 and Δ S t = + 62.8 J mol -1 K -1 . Adsorption indicates a similar transition in the pure NaBr surface at 268 K. It is proposed that, in the transition, anions acquire free two-dimensional translation. Comparison with exchange studies of Harrison & Siddiqui (1962) on solution-precipitated NaBr suggests that in those surfaces both anions and cations were mobile. Partly exchanged surfaces show non-ideal behaviour which is interpreted in term s of repulsion between like anions up to a threshold distance beyond which they attract each other. In KBr, the effects are large, and lead to formation of a surface compound K 4 Br 3 Cl. Beyond this composition further Cl - does not substitute into the KBr surface below 10 °C at ordinary HCl pressures. The transition temperature of KBr surfaces 5 to 15 % exchanged with Cl - is depressed. This is attributed to a tendency to two-phase separation of the surface as KBr and K 4 Br 3 Cl. In NaBr, corresponding interactions are weaker, and give only slight non-ideality. This has been matched by computations using the 'quasi-chemical’ aproximation, with first-neighbour repulsion of like anions about 2 kJ mol -1 and similar second-neighbour attraction. The effects are believed to be associated with the Verwey distortion. They are smaller in NaBr than in KBr because the former is being studied with anions in the mobile state in which such effects are only residual. Data for KBr suggest that, above its transition, it may lose these enthalpy effects more completely than NaBr and acquire an entropy-dominated non-ideality like that found by Harrison & Siddiqui (1962) in solution-precipitated NaBr.